Migrate terragrunt ignore to new template as suggested

Terraform.gitignore

@@ -32,7 +32,3 @@ override.tf.json
 # Ignore CLI configuration files
 .terraformrc
 terraform.rc
-
-# Ignore the default terragrunt cache directory
-# https://terragrunt.gruntwork.io/docs/features/caching/
-.terragrunt-cache

community/Terragrunt.gitignore

@@ -0,0 +1,3 @@
+# Ignore the default terragrunt cache directory
+# https://terragrunt.gruntwork.io/docs/features/caching/
+.terragrunt-cache